Lift truck fork for building bricks



H. PRlEsTER LIFT TRUCK FoRx FoR BulLDING BRIcxs Aug.v 15, 195o 3 Sheets-Sheet l Filed sept. 11. 1946 H. PRIESTER LIFT TRUCK FORK FOR BUILDING BRICKS 3 Sheets-Sheet 2 INVENT'OR Henry Praag-ier BY M 'Y r C RNEYs Aug. 15, 1950 Filed Sept. l1, 1946 IH; N

Aug. l5, 1950 H. PRlEsTER LIFT TRUCK Foxx Foa BUILDINGBRIcxs Filed Sept. ll, 1946 5 Sheets-Sheet 5 y LIlllillillll ilwlllll lllxl l INVENTOR Henry' Ff'z/ese?" E 7*"9 CHILE? V NEYS IIITI, 2..

Patented Aug. 15, 1950 LIFT TRUCK FORK FOR BUILDING` BRICKS Henry Priester, Middletown,` N. Y. y y

Application September 11, 1946, Serial No. 696,111

This invention relates to a lifting fork for building brick. The principal object of this invention is the provision of a lifting fork which is adapted to be used in conjunction with lift truck to transport large quantities of building brick from one place to another. It is the object of this invention to provide means for loading, carrying and unloading quantity units of brick without any manual operation other than that which is required tc operate the lift truck itself. Using a lifting fork in accordance with the present invention, a single worker operating an ordinary lift truck is able to drive over to a unit of building brick, load the unit, transport it and then unload it without touching a single brick. Of course the unit of brick must be laid in accordance with a ,pre-determined plan which takes into account the features and proportions of the lifting fork. But once this is done, the same unit may be moved into the kiln, left there for burning, and then removed therefrom to a place of storage. From there the unit may be moved to a truck or railroad car for transportation to the building job, and then removed from said truck or railroad car and deposited in a place which is accessible to the mason. All this can be done with the lifting fork herein claimed.

A preferred embodiment of this invention is shown in the accompanying drawing in which- Fig. l is a front elevational view of the lifting fork herein claimed;

Fig. 2 is a fragmentary plan View thereof;

Fig. 3 is a fragmentary end view of the suspension mechanism of the lifting fork;

Fig. 4 is a fragmentary fro-nt view partlybroken away to show in detail the gear mechanism of the lifting fork;

Fig. 5 is a detailed section on the line 5-5 of Fig. 4;

Fig. 5 is a section through the gear box on the line 6-6 of Fig. 4;

Fig. 7 is a fragmentary enlarged view of part of the gear mechanism;

Fig. 8 is a detailed fragmentary view partly in section showing the brick gripping mechanism of the lifting fork; and

Fig. 9 is a View Substantially similar to that of Fig. 8 showing a modified form of gripper.

The lifting fork herein claimed is adapted to be attached by means of a pair of bolts to the ylifting frame lil of any conventional lift truck. These bolts extend through holes and l2 in the suspension member i3 of the liftingr fork. This suspension member may comprise a length of angle steel as shown in the drawing,

5 claims. (o1. :n4-65.2)

It is suspension member I3 that the lift truck lifts and by virtue of such operation, the lifting fork hereinafter described is itself put into operation.y Mounted on the suspension member |3 at i4 is a rocking arm 5; This rocking arm supports at its ends rods 2l! and 2| respectively. These rods are vertically disposedand they lare adjustable as to length bymeans of couplings 23. The lower end of each of these rods supports a pair of rack gears 26'and 2'! respectively. These rack gears extend through a gear box or housing 28, and in said housing they engage a pair of gear wheels 29 and 3B respectively. These gear Wheels are relatively large and aiiixed to them are smaller gear wheels 3| and v32 respectively. These small gear wheels engage athird rack gear 35. A link 31 is pivotally connected at its Lipper end to the lower end of the third rack gear 35, and said link is pivotally connected at its lower end to an off-set portion of abell crank shaped clamp 38.` This clamp is fixed to a horizontall shaft 39, and said shaft 39 extends through the frame 40 of the lifting fork. 1

It will be apparent from the foregoing thatwhen the suspension member I3 which is con-y nected to the lifting frame of the lift truck israised, a corresponding upward'movementof the rocking arm |5 and the bolts 2U and 2| will be caused. This upward movement will -be transformed through the gear box into an upward movement of the third rack gear 35 of smaller extent. In other words the extent of travel of the third rack gear will be smaller than that of the rods 20 and 2|, and hence Vof the suspension member i3. This upward movement of the thirdl rack gear will be converted through the link 31 and the clamp SBVinto an angular movement of the shaft 39 upon the shafts longitudinal axis. When such angular movement of the shaft rceases for reasons which will hereinafter appear, the upward movement of the link 31 will"communicate itself through the shaft 39 to the frame 49 of the lifting fork. It is at this point, therefore, ythat the upward movementof the lifting frame' of the lift truck is transmited to the frame of the liftthereto to complete the framework, and said horizontal member 41 is also affixed to the horizontal tines 45. Course members 49 are affixed at pre-determined horizontal levels to the vertical posts 45 of the frame. These course members serve as back Arests for the several courses of brick which the lifting fork is adapted to carry. A shield or plate 52 is affixed to the course members to prevent dust and other foreign material from entering the gear box 28 and the rest of the vertically movable mechanism hereinabove described.

It will be noted that the tines 46 are provided with channels 53, one on each side of each tine. In these channels horizontal rods 60 are disposed, and it will be seen that a link 6| connects the inner ends of these rods to rocking arms 54 which, like clamps 38, are clamped to the shaft 39. These rods are mounted for movement along their longitudinal axes, and it will be evident that when the shaft 39 and the clamps 38 thereon are caused to engage in angular movement, a pulling action upon the rods 60 will be effected through the rocking arms 54 and the links 6|. Clamps 38, shaft 39 and rocking arms 54 comprise what amounts to a bell crank assembly, so that the vertical movement of the link 31 is converted into a horizontal movement of the links From the foregoing it will be understood that the vertical upward movement of the lifting frame of the lift truck is converted into a horizontal backward movement of the rods 50. And it will subsequently be seen that when such horizontal movement of the rods 50 is brought to a halt, further upward movement of the lifting frame of the lift truck will result in corresponding upward movement of the entire lifting fork assembly, It may be noted at this point that vertical rods 20 and 2| are provided with compression springs 65 and 65 respectively. Upward movement of these rods takes place against the action of these springs and hence when the lifting frame of the lift truck is lowered to its original position of rest, the springs 65 and 66 will urge the rods 20 and 2| back to their original position of rest. In consequence of the action of these springs a downward movement of the links 31 is caused, and hence a. forward horizontal movement of the rods 60.

Each rod 60 is provided with a plurality of slidable blocks 10, a plurality of slidable spacing sleeves 1|, a plurality of stop members 12 and a plurality of compression springs 13. Reference to Fig. 8 will show that the sequence of these several members is as follows: Stop member 12, spacing sleeve 1|, slidable block 10, compression spring 13, stop member 12, etc. Stop members 12 are the only members which are xedly mounted on the rods 50. This may be done by means of set screws or in any other conventional way.

Gripping members 15 are affixed at one end to the tines 46 in the channels formed between the parallel walls of said tines. It will be noted that these grippers 15 are so mounted on pins 16 which are aixed to said tines and that said pins are positioned adjacent the spacing sleeves 1| A link 11 is pivotally connected at one end to the slidable block and at its other end to the gripper '55. It will be understood that longitudinal movement of the slidable member 10 along the rods 60 will result in a pivotal movement of the gripper to the dotted position indicated in Fig. 8. Such pivotal movement is elected. When the lifting frame of the lift truck causes an upward movement of the entire vertically movable assembly of the lifting fork hereinabove described. As has already been indicated, when such vertical movement takes place, an inward horizontal movement of the rods is produced. Since the stop members 12 are fixedly mounted on said rods 60, they will move along with said rods and they will, therefore, bear against the forward end of compression springs 13. The rear end of said springs bear against the slidable blocks 10. When, accordingly, such horizontal movement of the stop members 12 takes place, such movement will be transmitted through the springs 13 to the blocks 10. The links 11 will thereby be actuated and they will, therefore, cause the outward pivotal movement of grippers 15 illustrated by the dotted lines in Fig. 8.

In Fig. 9 a modified form of gripper is shown. The members which correspond to the grippers 15 are pivotally connected at their free ends to a gripping plate or shoe 8|. Each such shoe is connected 'to two members 80 so that when these members 80 are moved outwardly to the dotted positions shown in Fig. 9, by reason of the action above described with respect to the grippers the shoe 8| will also move outwardly to the dotted position shown in Fig, 9. This outward position will necessarily be parallel to the original position indicated by the solid lines in Fig. 9. To assist in bringing the shoe 8| outwardly to the dotted line position of Fig. 9, a camming yaction is provided between an L-shaped block 82 which corresponds to the stop members 12 above described and a beveled block 83 which is afixed to the inside of the shoe 8 I.

The action of the grippers upon the buildingr bricks' 98 is shown in Fig. 2. Each tine 45 is provided with a double row of grippers, one row on each side oi the tine, therefore. There are two rows of such grippers between adjacent tines. A double row of bricks 99 is laid down between adjacent tines in the position shown in Fig. 2. When an upward movement of the lifting frame of the liit truck takes place, such movement is converted in the first instance as has already been indicated, to an outward movement of the grippers. This outward movement will bring the grippers into tight contact with the bricks 9G. When movement of the gippers against the bricks ceases, further upward movement of the lifting frame of the lift truck will be translated into corresponding upward movement of the entire lifting fork assembly. Since the grippers are in tight contact with bricks 55, these bricks will be lifted by and with the lifting fork. The course of brick `as shown in Fig. 2, may be designated as the tine course. Additional courses may be laid upon the tine course and upon the tines, as is .shown in Fig. 5. Each course of brick is provided with a back stop in the form of the horizontal barsl 49 hereinabove described. This, too, is shown in Fig. 5. The grippers 8| are used in the same manner as the grippers 15 as shown in lT ig. 2. The sole difference is that these grippers 8| provide a line or plane Contact with the bricks, whereas the grippers 15 provide only a point contact with the bricks.

The above description as has been indicated, is a description of a preferred embodiment of the invention and it is presented solely by way of illustration and not by way of limitation. It will be appreciated that the structural and mechanical features of the present device as above described, may be modified in a great many ways without any departure from the basic principles ci the invention. In all modifications, however, one principle should be present, namely, that an upward movement of the lifting frame of the lift truck should be translated into a horizontal gripping movement of the brick grippers before it is transformed into a corresponding upward movement of the lifting fork assembly as a whole.

I claim:

1. In combination with a lift truck having a lifting frame, a lifting fori: having plurality of horizonte` 4y movable gripping members connected to the tinesI thereof, a vertically .movable construction on connected at its upper end tl'le lifting frat-rie of; the truck, and bell nr sm connected to the lcv-.fer end oi' vertic movable construction by means of a reduction system and means also connecting said bell crank mechanism to the horizontally moi/'able gripping members, whereby a vertical movement oi the lifting frame causes a horizontal movement of the gripping rnemb rs, iurt" er vertical movement of the liiting iL ame resulting in corresponding vertical movement oi the entire fork assembly when horizontal movement of the gripping members is brought to a halt.

2. In combination with a lifting mechanism, a lifting fork, a plurality of laterally movable brick gripping members connected to the tincs of said fork, vertically movable means including a gear reduction system for causing such lateral moveto the lifting frame of the truck, a vertically movable linkage having its upper end connected to said suspension member and its lower end oonnected to a bell crank mechanism, said linkage including a gear system, rods and links, said rods having their upper ends connected to the suspension member and their lower ends provided with rack gears meshing with said gear system, said links having their upper ends provided with rack gears meshing with said gear system and their lower ends connected to said bell crank mechanism that is operatively connected to said gripping members, the provision and arrangement being such that initial vertical movement of the lifting frame causes the brick gripping members to operate and continuing vertical movement results in the lifting of the entire fork assembly.

fi. A lifting fork as set forth in claim 3 and adjustable coupling members on said rods to regulate the inward movement of said gripping members. f

5. A lifting fork as set forth in claim 3 and compression springs positioned around said rods to return the brick gripping members to their normal position when the fork is returned to a ilat surface,

HENRY PRIESTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 954,584 Peniield Apr. 12, 1910 975,713 Peneld Nov. 15, 1910 LizB-l Allen Jan. 19, 1915 1,745,743 Crum Feb. 4, 1930 1,800,971 Wallace Apr. 14, 1931 2,933,746 Sullivan Mar. 10, 1936 2,323,810 Fontaine July 6, 1943 2,418,693 Breslav Apr. 8, 1947 

